1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "alsa_device_proxy"
18 /*#define LOG_NDEBUG 0*/
19 /*#define LOG_PCM_PARAMS 0*/
20
21 #include <log/log.h>
22
23 #include <errno.h>
24
25 #include "include/alsa_device_proxy.h"
26
27 #include "include/alsa_logging.h"
28
29 #define DEFAULT_PERIOD_SIZE 1024
30 #define DEFAULT_PERIOD_COUNT 2
31
32 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
33
34 static const unsigned format_byte_size_map[] = {
35 2, /* PCM_FORMAT_S16_LE */
36 4, /* PCM_FORMAT_S32_LE */
37 1, /* PCM_FORMAT_S8 */
38 4, /* PCM_FORMAT_S24_LE */
39 3, /* PCM_FORMAT_S24_3LE */
40 };
41
proxy_prepare(alsa_device_proxy * proxy,alsa_device_profile * profile,struct pcm_config * config)42 void proxy_prepare(alsa_device_proxy * proxy, alsa_device_profile* profile,
43 struct pcm_config * config)
44 {
45 ALOGV("proxy_prepare(c:%d, d:%d)", profile->card, profile->device);
46
47 proxy->profile = profile;
48
49 #ifdef LOG_PCM_PARAMS
50 log_pcm_config(config, "proxy_setup()");
51 #endif
52
53 if (config->format != PCM_FORMAT_INVALID && profile_is_format_valid(profile, config->format)) {
54 proxy->alsa_config.format = config->format;
55 } else {
56 ALOGW("Invalid format %d - using default %d.",
57 config->format, profile->default_config.format);
58 proxy->alsa_config.format = profile->default_config.format;
59 }
60
61 if (config->rate != 0 && profile_is_sample_rate_valid(profile, config->rate)) {
62 proxy->alsa_config.rate = config->rate;
63 } else {
64 ALOGW("Invalid sample rate %u - using default %u.",
65 config->rate, profile->default_config.rate);
66 proxy->alsa_config.rate = profile->default_config.rate;
67 }
68
69 if (config->channels != 0 && profile_is_channel_count_valid(profile, config->channels)) {
70 proxy->alsa_config.channels = config->channels;
71 } else {
72 proxy->alsa_config.channels = profile_get_closest_channel_count(profile, config->channels);
73 ALOGW("Invalid channel count %u - using closest %u.",
74 config->channels, proxy->alsa_config.channels);
75 }
76
77 proxy->alsa_config.period_count = profile->default_config.period_count;
78 proxy->alsa_config.period_size =
79 profile_get_period_size(proxy->profile, proxy->alsa_config.rate);
80
81 // Hack for USB accessory audio.
82 // Here we set the correct value for period_count if tinyalsa fails to get it from the
83 // f_audio_source driver.
84 if (proxy->alsa_config.period_count == 0) {
85 proxy->alsa_config.period_count = 4;
86 }
87
88 proxy->pcm = NULL;
89 // config format should be checked earlier against profile.
90 if (config->format >= 0 && (size_t)config->format < ARRAY_SIZE(format_byte_size_map)) {
91 proxy->frame_size = format_byte_size_map[config->format] * proxy->alsa_config.channels;
92 } else {
93 proxy->frame_size = 1;
94 }
95 }
96
proxy_open(alsa_device_proxy * proxy)97 int proxy_open(alsa_device_proxy * proxy)
98 {
99 alsa_device_profile* profile = proxy->profile;
100 ALOGV("proxy_open(card:%d device:%d %s)", profile->card, profile->device,
101 profile->direction == PCM_OUT ? "PCM_OUT" : "PCM_IN");
102
103 if (profile->card < 0 || profile->device < 0) {
104 return -EINVAL;
105 }
106
107 proxy->pcm = pcm_open(profile->card, profile->device,
108 profile->direction | PCM_MONOTONIC, &proxy->alsa_config);
109 if (proxy->pcm == NULL) {
110 return -ENOMEM;
111 }
112
113 if (!pcm_is_ready(proxy->pcm)) {
114 ALOGE(" proxy_open() pcm_open() failed: %s", pcm_get_error(proxy->pcm));
115 #if defined(LOG_PCM_PARAMS)
116 log_pcm_config(&proxy->alsa_config, "config");
117 #endif
118 pcm_close(proxy->pcm);
119 proxy->pcm = NULL;
120 return -ENOMEM;
121 }
122
123 return 0;
124 }
125
proxy_close(alsa_device_proxy * proxy)126 void proxy_close(alsa_device_proxy * proxy)
127 {
128 ALOGV("proxy_close() [pcm:%p]", proxy->pcm);
129
130 if (proxy->pcm != NULL) {
131 pcm_close(proxy->pcm);
132 proxy->pcm = NULL;
133 }
134 }
135
136 /*
137 * Sample Rate
138 */
proxy_get_sample_rate(const alsa_device_proxy * proxy)139 unsigned proxy_get_sample_rate(const alsa_device_proxy * proxy)
140 {
141 return proxy->alsa_config.rate;
142 }
143
144 /*
145 * Format
146 */
proxy_get_format(const alsa_device_proxy * proxy)147 enum pcm_format proxy_get_format(const alsa_device_proxy * proxy)
148 {
149 return proxy->alsa_config.format;
150 }
151
152 /*
153 * Channel Count
154 */
proxy_get_channel_count(const alsa_device_proxy * proxy)155 unsigned proxy_get_channel_count(const alsa_device_proxy * proxy)
156 {
157 return proxy->alsa_config.channels;
158 }
159
160 /*
161 * Other
162 */
proxy_get_period_size(const alsa_device_proxy * proxy)163 unsigned int proxy_get_period_size(const alsa_device_proxy * proxy)
164 {
165 return proxy->alsa_config.period_size;
166 }
167
proxy_get_period_count(const alsa_device_proxy * proxy)168 unsigned int proxy_get_period_count(const alsa_device_proxy * proxy)
169 {
170 return proxy->alsa_config.period_count;
171 }
172
proxy_get_latency(const alsa_device_proxy * proxy)173 unsigned proxy_get_latency(const alsa_device_proxy * proxy)
174 {
175 return (proxy_get_period_size(proxy) * proxy_get_period_count(proxy) * 1000)
176 / proxy_get_sample_rate(proxy);
177 }
178
proxy_get_presentation_position(const alsa_device_proxy * proxy,uint64_t * frames,struct timespec * timestamp)179 int proxy_get_presentation_position(const alsa_device_proxy * proxy,
180 uint64_t *frames, struct timespec *timestamp)
181 {
182 int ret = -EPERM; // -1
183 unsigned int avail;
184 if (proxy->pcm != NULL
185 && pcm_get_htimestamp(proxy->pcm, &avail, timestamp) == 0) {
186 const size_t kernel_buffer_size =
187 proxy->alsa_config.period_size * proxy->alsa_config.period_count;
188 if (avail > kernel_buffer_size) {
189 ALOGE("available frames(%u) > buffer size(%zu)", avail, kernel_buffer_size);
190 } else {
191 int64_t signed_frames = proxy->transferred - kernel_buffer_size + avail;
192 // It is possible to compensate for additional driver and device delay
193 // by changing signed_frames. Example:
194 // signed_frames -= 20 /* ms */ * proxy->alsa_config.rate / 1000;
195 if (signed_frames >= 0) {
196 *frames = signed_frames;
197 ret = 0;
198 }
199 }
200 }
201 return ret;
202 }
203
204 /*
205 * I/O
206 */
proxy_write(alsa_device_proxy * proxy,const void * data,unsigned int count)207 int proxy_write(alsa_device_proxy * proxy, const void *data, unsigned int count)
208 {
209 int ret = pcm_write(proxy->pcm, data, count);
210 if (ret == 0) {
211 proxy->transferred += count / proxy->frame_size;
212 }
213 return ret;
214 }
215
proxy_read(const alsa_device_proxy * proxy,void * data,unsigned int count)216 int proxy_read(const alsa_device_proxy * proxy, void *data, unsigned int count)
217 {
218 return pcm_read(proxy->pcm, data, count);
219 }
220
221 /*
222 * Debugging
223 */
proxy_dump(const alsa_device_proxy * proxy,int fd)224 void proxy_dump(const alsa_device_proxy* proxy, int fd)
225 {
226 if (proxy != NULL) {
227 dprintf(fd, " channels: %d\n", proxy->alsa_config.channels);
228 dprintf(fd, " rate: %d\n", proxy->alsa_config.rate);
229 dprintf(fd, " period_size: %d\n", proxy->alsa_config.period_size);
230 dprintf(fd, " period_count: %d\n", proxy->alsa_config.period_count);
231 dprintf(fd, " format: %d\n", proxy->alsa_config.format);
232 }
233 }
234